Question

Si a+b+c=5 y ab+bc+ac=4 calcule a²+b²+c²

Answer 1

Respuesta:

17

Explicación paso a paso:

$(a+b+c)^{2} =a^{2}+b^{2} +c^{2} +2ab+2ac+2bc\\(a+b+c)^{2} =a^{2}+b^{2} +c^{2} +2(ab+ac+bc)\\(5)^{2} =a^{2}+b^{2} +c^{2} +2(4)\\25 =a^{2}+b^{2} +c^{2} +8\\25-8=a^{2}+b^{2} +c^{2}\\17=a^{2}+b^{2} +c^{2}$